You are here
Hyperelasticity
Mon, 2015-03-02 19:25 - Settler7
Hello all,
I would like to ask you your opinion on the following statement "At this time there is no method that can identify a unique set of hyperelasticity parameters for compression and simple shear deformation" [1].
I am particularly interested in this statement, as I am trying to model the behavior in compression and shear for rubber with steel laminates, and have hard time matching the experimental with FEM results.
Thank you in advance!
1. Amin, A. F; Wiraguna, S. I; Bhuiyan, A. R; Okui, Y, "Hyperelasticity Model for Finite Element Analysis of Natural and High Damping Rubbers in Compression and Shear", Journal of Engineering Mechanics, ISSN 0733-9399, 01/2006, Volume 132, Issue 1, pp. 54 - 64
Forums:
The quotation is referencing
The quotation is referencing work where a hyperelastic model was calibrated to uniaxial data only and then found that this does not characterize the comperession or shear behavior of the material. That whole section of the paper can be summarized with "Fitting a material model to only one deformation regime will often give poor results in other deformation regimes."
So the takeaway is that you should use all of the different types of tests simultaneously when fitting hyperelastic models. By minimizing the error in the model across all of the tests you have the best chance of matching the real-world behavior. However, it is always possible that a particular model might not be able to match all the tests well.
For your problem I'd make sure my rubber material was well-calibrated using several types of tests (uniaxial tension and compression, biaxial, planar, and volumetric, if you're using Abaqus) against experiment with just the rubber. Then you can build up a composite model using the individual materials. If you are confident in the material models, and you still get poor results to experiment, I'd look at how the different materials are bonded as the next source of error.
I hope that helps!